Process for treating lactic fluids



Nov. 26, 1935. '5, w HAMMER ETAL 1 2,022,420

PROCESS FOR TREATING LACTIC FLUIDS Original Filed March 25, 1935 10 Sheets-Sheet 1 mm: mm

\ Mr- WHOM Nov. 26, 1935. B. w. HAMMER El AL 2,022,420

PROCESS FOR TREATING LAGTIC FLUIDS Original Fi led March 25 1955 10 Sheets-Sheet 2 Zinnentors Y I Z0. fiamme/L Her/nah 6. ffavvmnvan jftlbm 55'. 7 22/1502 Nov. 26, 1935. B. w. HAMMER ET AL 2,022,420

PROCESS FOR TREATING LACTIC FLUIDS Original Filed Max Ch 26, 1935 10 Sheets-Sheet 3 iii /s /mm e M Mttomeus Nov. 26, 1935. B, w HAMMER r A 2,022,420

PROCESS FOR TREATING LACTIC FLUIDS Original Filed March 26, 1935' 10 Sheets-Sheet 4 13? V g Snnentms fiQ/fiO/d 6. Hammer:

Herman CI Horne/nan.

30 i- I I I M l'g wattorneg Nov. 26, 1935. B. w. HAMMER ET AL 2,022,420

PROCESS FOR TREATING LACTIC FLUIDS V Original Filed March 25, 1935 10 Sheets-Sheet 5 Zhwentors flerflard w lfeuflmer; Her-man C. fiorneman.

Mixer;

Original Filed March 26, 1935 10 Sheets-Sheet 6 w mm m 1 M61 m wfm w m w M V 5 w j Mg 0 m? M w w J w W 9 w J W 4 'lIW' IWHH\ w m Nov. 26, 1935. B. w. HAMMER ET AL PROCESS FOR TREATING LACTIC FLUIDS 10 Sheets-Sheet' 7 Original Filed March 26, 1935 Zmventors @fflafd 606%10/11/112/1 fie/man C. 740711011017- Mwfl/Jf Wide .1

A Mmu/ Gttornegs Nov. 26, 1935.

B. W. HAMMER ET AL PROCESS FOR TREATING LACTIC FLUIDS ori inal Filed March 26, 1935 10 Sheets-Sheet 8 l m W flernara fie/man CZ Nov. 26, 1935. B. w. HAMMER El AL'. 7 2,022,420

' PROCE SS FOR TREAT'INGYLACVTIC FLUIDS Original Filed Mafch '26, 1935 10 Shets-Sheet 9 fie/ward 20. 1-1czmmez; Her/710 161 flornemarn Nov. 26, 1935. B. w. HAMMER ET AL 2,022,420

PROCESS FOR TREATING LACTIC FLUIDS Original Filed March 26, 1955 10 Sheets-Sheet 1o 3nnentors @rnard Z iv ammerg Herman C fiorwema/L .mnj'i' fluke/I.

Patented Nov. 2 6, 1935 erred Ares PATENT amaze PROCESS FOR TREATING LACTIC FLUIDS land Original application March 26, 1935, Serial No. 13,168. Divided and this application July 19,

1935, Serial No. 32,284

15 Claims. (Ci 99-11) This invention relates to a process of (1) pasteurizing liquids; (2) deodorizing liquids (i. e., removing undesirable odors and elf-flavors) and (3) cooling liquids. The process and/or apparatus are useful for accomplishing any two of these operations, or particularly, for carrying out all three, as an intermittent, continuous or simultaneous treatment. The invention is used in connection with various classes of liquids and fluids, of which milk, cream, and lactic fluids in general are exemplary.

Milk products such as milk or cream often have characteristic odors'and flavors which are undesirable and must be removed. These develop from various sources and during certain periods of the year. odors and flavors are stubborn and tenacious and require drastic treatment to denude the lactic While conventional methods of pasteurizing' and cooling lactic fluids such as milk or cream, do, to a limited extent, tend to improve the flavor and odor of these products by partially volatilizing the off-flavor and undesirable odor" imparting substances therefrom, the present invention so augments and enhances this volatilizing ellect as to reduce the oil-flavors and odors tov a negligible or substantially imperceptible quantity in the end product.

Briefly stated, the invention initially provides a steam treatment for (1) pasteurizing a fluid, for example, cream, and (2) subdividing the cream to release undesired substances and ren der those remaining in the cream, which may be in excessive concentration and/or persistent, potentially releasable, i. e., removable by subsequent treatment of the cream. This initial treatment takes place upon a travelling confined mass of the fluid-steam mixture.

Preferably, as a subsequent and continuous operation with the initial treatment, the par-- teurized and subdivided cream in the form of a cream-steam-water mixture is continuously introduced through a reduced outlet into a vacuum chamber where, under conditions of reduced pressure, it, spontaneously and with violent and explosive force, expands into a fog or mist-like state. This final state of subdivision of the pre limlnarlly treated cream permits separation of Many of these objectionable the undesirable volatiles simply and completely and recovery of the cream substantially .devoid of objectionable oil-flavors and odor imparting substances.

In the preferred form of the invention, the cream is compressed and heated; live steam at high temperature and the compressed cream are then formed into fine streams or jets of high velocity. The two jets are directed so as to intersect with violent agitation, whereby the cream is bombarded and shattered or sheared by the steam. Stated another way, two high velocity intersecting streams respectively of steam and cream are produced, the velocity of the cream being assisted by the aspirating effect of the steam, and the bombardment or contact of cream and steam results in heating of the cream, with (1) simultaneous tearing apart of the cream particles and subdivision thereof and intimate mixture of the steam with the cream, forming a cream-steam-water mixture having substantially a mist-like form, and (2) concomitant expansion of the mixture with enhanced tearing apart of the cream particles, in the zone of low pressure created by the high velocity streams.

As one means for accomplishing these effects, we employ a Venturi type of injector device having' means for producing separate steam and cream jets of high velocity and in which the cream-steam-water mixture so formed is caused to expand by reason of the reduced pressure obtaining in the gradually enlarging side of the venturi and leading to a conduit which communicates with the vacuum chamber. very fine subdivision is produced, namely, the resultant of (1) the discharge of the cream at high velocity through a reduced opening, (2) the bombarding and heating of the cream stream with steam at high velocity, and (3) the expan sion of the cream-steam-water mixture in the tapering outlet in the venturi which latter increases in diameter toward its jointure with the conduit. This preliminary treatment will condition cream having excessive concentrations of oil-flavors and odoriferous substances of the most tenacious nature, and result in the release of a substantial portion of these as volatiles and Hence, a

render the remainder potentially releasable to the water mixture in cooperation with the reduced.

sure in the venturi, the velocity decreases and the conduit or line leading to the vacuum chamber becomes filled with the cream-steam-water mixture as a liquid column under increasing pressure. As will be understood, the fluid confined in the line will be under an increased pressure accompanied by a decrease in velocity, e. g., in accordance with the quantitative law with regard to changes inpressure and changes in speed as expressed by Bernoulli's theorem. The cream is pasteurized and further condition to enhance the release and potential release of undesired substances during travel in the line or conduit and the compressed cream-steam-water mixture is introduced into the vacuum chamber through. a reduced outlet, spontaneously and violently assuming a fog or mist-like state.

We have also discovered, as a modification and in lieu of the initial treatment just described, that pasteurization and subdivision of the cream particles is satisfactorily accomplished by injecting live steam under pressure in the form of needlelike jets into a travelling liqu d column of cream and producing a.multiplicity of impacts or impingements by the steam upon the cream whereby mixture of the steam and cream takes place in a manner to agitate and thoroughly comb the cream with steam. At the same time, this treatment imparts to the mixture a turbulent and whirling movement in the direction of travel of the cream toward the vacuum chamber.

In each of the processes described, the cream is preliminarily (l) pasteurized at high temperatures in the line, (2) intimately mixed with steam and agitated and shattered, i. e., the cream particles are torn apart and subdividedby the steam and (3) conditioned to have the objectionable volatiles released or rendered potentially releas-.

able.

In the initial steam treatment, thelatent heat of the steam is very largely transferred to the cream and 1) part of the steam condenses and (a) the heat of condensation also is transferred to the cream, resulting in a cream-steam-water mixture having a pasteurizing or sterilizing temperature 01 substantially 200 to 250 F. or higher; (b) the condensation oi the steam with sudden collapse or the steam bubbles upon coming in .contact with relatively cooler cream will cause a breaking up of the fat globules wth consequent release or potential release volatile odoriferous substances occluded within the fat globules, and (c) the heating eiiect, the release of volatiles, and the uncondensed portion oi! the steam produces a compression, and (2) the uncondensed steam exerts a sweeping action in that it serves as a carrier for the volatile or vapor phase constituents of the cream released by the shattering actions and heating eflect of the steam.

The cream-steam-water mixture is compressedin the line or conduit- (a) due to the heating ei-' pressure in the vacuum chamber and the reduced outlet in the distributor'head causes the mixture to be discharged into the vacuum chamber with explosive and violent expansion whereby mixture spontaneously assumes a substantially foglike state. As will be appreciated, the fluid, while travelling to the vacuum chamber, is constantly treated and conditioned, being (a) heated, compressed, expanded and compressed, or (b) heated 5 and compressed, and then (0) in either case, expanded in the vacuum chamber. As stated, the preliminary treatment and conditioning takes place while the cream is travelling in the line and the cream is preferably continuously introduced therefrom into the vacuum chamber, providing a continuous system. It is considered that the optimum conditioning of the cream is due to the presence of each of the several factors outlined which co-operate with each other to afiord a preliminary treatment such that the final product is of enhanced quality and the operation economical and universal for plant practice.

By pasteurizing is meant heating the fluid during travel through the conduit in direct contact with the steam and within both the conventional flash pasteurizing range of substantially 165 to 190 F., and particularly at higher temperatures, i. e., above the normal flash pasteurizing temperatures and within'a sterilization range of substantially 200 to 250 F. or higher. In other words, pasteurization at a high temperature, that is, above the boiling point of the fluid at normal atmospheric pressure, is accomplished with this invention. I

With respect to the vacuum chamber, we have found that by recourse to either of the preliminary treatments described, and the use of a distributor head having a reduced outlet, optimum advantage can be had of the reduced pressure maintained within the vacuum chamber. That is, the cream is conditioned in the line for optimum expansion in the vacuum chamber so that the two stages or steps are interdependent and assure the desired final result, namely, a cream substantially denuded of its objectionable characteristics. The vacuum chamber affords a simple and eiilcient means of separating and removing the vapor phase constituents, including the undesirable volatiles, irom the cream.

The vacuum chamber is characterized by being heated. In this manner condensation of water vapors and condensable odoriierous and oil-flavor imparting volatiles and their attendant objectionable return to the cream is prevented; likewise separation of liquid and vapor phase constituents is maintained or prolonged, and, moreover, complete separation of liquid phase particles of cream is obtained.

As will be appreciated, wheresteam is used, a cream-steam-water mixture will be produced, I

- while the lactic product is initially heated under compression, and the expansion treatment oi this creamsteam-water mixture in the vacuum chamber is characterized by removal or moisture 6 and odoriierous-and off-flavor imparting substances. As a result, the end product has improved organoleptic qualities and a moisture content substantially that of the original cream.

" That is, although dilution will take place in the berand the mixture is condensed-whereby the flnal' efl'ect is one of recovering the cream in substantially its original volume but denuded of objectionable flavors and odors.

Another advantageous step of the process 01' this 'invention, as where the concentration 0! off-flavors and/or odors is excessive or of a stubborn nature, resides in subjecting the cream either (1) to a preliminary steam scrubbing or deodorizing distillation treatment prior to the initial compression, and subsequent expansion in the vacuum chamber as above described, and/or (2) to a similar scrubbing (a) continuously in the presence of the expansion treatment, (b) continuously in a separate chamber, or (c) in batch in the vacuum chamber or a separate chamber.

Preferably, the cream is continuously collected in the vacuum chamber, and successive portions thereof are continuously subjected in the vacuum chamber, during the expansion treatment therein to a steam scrubbing accompanied by odor and off-flavor removal. This operation removes additional, i. e., remaining odor and flavor imparting, substances from the cream and is preferably simultaneous and continuous with the forming of the mist or fog by the violent and spontaneous expansion of the creamsteam-water mixture in the vacuum chamber.

In some cases, the scrubbing treatment is carried out in a separate vacuum chamber, the scrubbing with steam being continuous with the expansion treatment in the other vacuum chamber. Again, intermittent batches are (1) scrubbed in a separate chamber; or (2) are scrubbed in the same vacuum chamber upon completion of the expansion treatment therein.

The advantage of having the scrubbing substantially immediately follow or be continuous with the expansion treatment in any of the processes described resides in the saving effected, in that the cream will be at a temperature such that reheating thereof is unnecessary as a preliminary to scrubbing.

This scrubbing takes place upon the cream while the latter is at its boiling point under thecondition of vacuum being maintained. The live steam at high temperature and pressure, e. g. around 325 F. and eighty pounds gauge, is iniected into the mass of cream at the bottom thereof and immediately expands, sweeping through the cream and mechanically removing objectionable odor and flavor imparting substances. No substantial evaporation of the cream takes place and the efiect therefore is one wherein the steam agitates and passes through the cream without,

appreciably raising the temperature of the cream, but at the same time, releases and carries off the undesired substances.

A primary object of this invention is to provide means for pasteurizing a fluid such as cream at temperatures considerably higher than those conventionally used and without detrimental effect upon the final product. This is made possible by the rapid heating and instantaneous cooling to which the lactic fluid is subjected whereby pasteurizing temperatures of substantially 200 to 250 F. or higher may be safely employed. In other words, in conventional operations the temperatures of pasteurization must be below the boiling point of the lactic fluid being treated at normal atmospheric pressure, whereas, with the present invention, this limitation does not obtain.

By rapid heating is meant the heating of a continuously flowing mass travelling at a speed of the order of substantially three to five pounds (about /2 gallon) per second past a given point under'the high. temperatures recited and under a pressure of substantially ten pounds gauge and higher.

In referring to instantaneous cooling, we mean .Figure 7.

spontaneous cooling obtained by suddenly releasing the pressure on the heated fluid in the conduit, e. g., by introduction of the fluid into a vacuum chamber, whence it assumes, by reason of the cooperation of a, distributing head having 5 a restricted outlet, a finely divided or mist-like condition and undergoes a sharp and immediate reduction in temperature induced by the reduced pressure in the vacuum chamber.

This combination of steps in a continuous operation, of rapid heating and instantaneous cooling with reduction of the fluid to a fog-like state,- (thereby exposing maximum surface for cooling) permits utilization of high temperatures within the sterilization range and Without detrimental effects on the organoleptic and physical characteristics of the final product.

In fact, it has'been found that the physical characteristics of the product, e. g., cream, are actually enhanced, whereby the stability of the finally recovered cream emulsion is improved to the extent that separation of the cream into a cream and skim milk layer is prevented. Furthermore, the stability of the recovered cream emulsion,.i. e., the final product, is such as to 25 minimize, and in most instances eliminate, the so-called feathering of cream when used in coffee or other hot beverage. This enhanced stabilizing efiect is also valuable in the processing of ice cream mix and the pasteurization of milk used in the manufacture of cheese, concentrated milks, fermented milks, and milk powder. The stabilizing effect is so definite that, milk powder made from milk thus treated possesses improved properties when used in baking applications. 35 This stabilizing effect is due to the greatly enhanced dispersion of fat globules and the increased viscosity of the milk, resulting from (a) the shattering effect during the preliminary treatment promoting dispersion, and (b) the subsequent spontaneous expansion in the vacuum chamber providing instantaneous cooling.

Another important feature of the invention is to provide eflective control of the temperature and pressure conditions and assure that the cream, for example, will be thoroughly pasteurized and rendered in the optimum state for treatment in the vacuum chamber.

The present invention embodies process and apparatus inclusive of the subject matter of the 50 applications of Herman C. Horneman, SerialoNo. 654,069, filed January 28, 1933, and Serial No. 681,656, filed July 21, 1933, and relates to improvements thereon.

Other objects and novel features and advan- 65 tages of this invention will be apparent from the 'following specification and the accompanying drawings. In the drawings,

Figures 1 and 2 are plan views partly in section of the preferred process and apparatus for 60 practicing the invention;

Figure 12 is a side elevation including a plur'ality of vacuum chambers or vacuum-chamberscrubbers connected so as to be selectively operable, this construction being used in association with any of the apparatus shown in Figures 1 to 11 and 25 to 29; v

Figure 13 is a detail sectional view of a preferred type of steam injection apparatus, useful in connection with each of the apparatus of Figures 1 to 12 and 25 to 29;

Figure 14 is a section on the line l4--|4 of Figure 13;

Figures 15 and 16 aredetail sectional views of another form of steam injection apparatus and useful in association with the apparatus of Figures 1 to 12 and 25 to 29;

Figure 17 is an end view of one of the nozzles of Figures 15 and 16 looking toward the line li-l'|;

Figures 18, 19 and 20 are views partly in sec tion and partly in elevation, and broken away, showing a surge tank and several types of float valve mechanism associated therewith, used in connection with the apparatus of Figures 1 to 12 and 25 to 29;

Figures 21 to 24 are sectional views of distributor heads each having a restricted outlet, and employed with each of the apparatus of Figures 1 to 12 and 25 to 29;

Figures 25 to 28 are sectional views of vacuum chambers or stills useful in connection with each of the apparatus of Figures 1 to 12;

Figure 29 is a detail section showing electrical resistance means for heating the wall of the vacuum chamber or still;

Figure 30 is a diagrammatic view showing the preferred process in accordance with the present invention;

Figure 31 is a similar view, partly broken away of another process; and

Figure 32 is a similar view showing a still further process.

In general, the apparatus and process is similar to that shown and described in the aforesaid Horneman applications, embodying, however, improvements which render the invention more flexible and eflicient both as regards the quality of end product recovered and economics of operation.

In Figures 1 to 12, the numeral 9 represents a closed metal container equipped to operate as a vacuum chamber and also in some cases as a vacuum scrubber or still. This vacuum chamber is preferably heated as will be later ,described. The liquid to be treated is introduced into a surge tank l8 through a pipe H from a forewarmeror other means where it,has been preliminarily heated to a suitable temperature and/or otherwise treated. The surge tank I0 is provided with a float controlled outlet l2, as shown in Figures 18, 19 and 20. The outlet I2 is connected by a pipe iii to a motor operated pump P, preferably of the positive type, capable of impressing a pressure of five to fifty pounds, or more, on the liquid. The liquid is pumped through the pipe It to a line comprising pipes or conduits A-B suitably connected, and from a the conduit B is introduced into the vacuum 24. Referring to Figures 1, 2, 6 and 12, a steam injection-device C shown in detail in Figures 13 and 14, is interposed between the pump P, pipe .andthepipeA; inFigures5',7, 8, 9 and 11.

, ber.

another type of steam injection device D, shown in detail in Figures 15 and 16, or an injection device as provided in said Horneman applications, is disposed in the line A. If desired, the two devices C and D may be combined. In such event, the steam injection means D is used for forewarming the cream supplied to the surge tank l0, being interposed in the line I l, and the usual forewarmer, e. g., flash pasteurizer or barrel heater, omitted. Either of the steam injection means C or D or both are used in association with each of the apparatus shown in Figures 1 to 12 and 25 to 29. This, briefly, describes the general system employed and details of the apparatus will be further elucidated.

The invention is useful for treating a large variety of liquids, and finds particular utility in the case of lactic fluids such as milk and cream. These, as heretofore stated, often possess objectionable odors and off-flavors, and the invention will be exemplified in the removal from cream of substances imparting such undesired characteristics.

Generally stated, the cream is (a) pasteurized within a sterilization range while travelling in the line A- B and/or pipe 15 by reason of live steam which is preferably introduced at proper pressure and temperature; (5) the cream particles are torn apart by agitation and impact with the steam and this shattering action, which takes place while the cream is moving from the pump to the vacuum chamber, releases the off -flavor and odoriferous substances and/or renders them potentially releasable; (c) the cream-steam-water mixture is discharged through the reduced outlet of the distributor head I6 and spontaneously with explosive-force expanded to a mist or fog-like state; (d) a heated vacuum chamber is employed whereby condensation of vapor phase constituents is prevented and separation of liquid and vapor phase constituents is prolonged; and (e) maximum subdivision of the cream particles is obtained in the vacuum chamber enabling substantially complete removal of the odoriferous and offflavor imparting volatiles. The very effective results are made possible 1) by the efliciency of the preliminary subdivision of the cream while travelling to the vacuum chamber and (2) by the'cooperation of the vacuum treatment, whereby the cream is substantially denuded of undesired volatiles, or by simple and inexpensive subsequent treatment rendered so.

Stated briefly, the cream, while travelling in the line A--B or A-B-IS, is compressed, due to the cooperation (a) of the heating effects, (b) of let in the distributor head is at the other end of the system, and (d) the steam at high pressure and temperature which is introduced into the crcam and also cooperating with said restricted outlet; thereafter the cream-steam-water mixture is violently expanded in the vacuum cham- In the case of the steam injector device shown in Figure 13 in detail and in Figures 1, 2, 6 and 12, the cream is heated in the Venturi device and compressed between the pump at one end and the restricted Venturi port at the other, then projected through the port at high velocity as a thin stream or cone into contact with an intersecting thin jet or cone of live steam at high velocity, with accompanying decrease in pressure, and the cream-steam-water mixture is expanded in the gradually enlarging Venturi outlet; thereafter the mixture fills the line A as a liquid column and is under the pressure created by the heating effect, the pump, distributor head and steam pressure, as above described.

The heating of the continuously travelling cream, in addition to accomplishing pasteurizing or sterilizing. also acts to agitate the cream whereby the cream particles are shattered and torn, and

the released objectionable substances are vole tilized and retained in this condition so that they are readily removable in the vacuum chamber as vapor phase constituents. 'At the same time, the breaking up of cream particles assures uniform and minute subdivision and uniform heating for pasteurizing and sterilizing; of equal im portance and, in fact, of particular significance, Where the odor or off-flavor imparting substances are tenacious and/or excessive, this preliminary and intimate subdivision renders such stubborn substances potentially releasable, i. e., readily re movable as vapor phase constituents by the vacuum chamber treatment or by a. simple and inexpensive further treatment as will be later set forth.

Referring to Figures 1, 2, 6, 12, 13 and 14, the steam injection means C has a steam inlet it come municating with a steam line i8 and a fluid inlet l9 communicating with the outlet pipe M of the pump P. This steam injection means has the form of a venturi but any suitable construction capable of producing heating and compression of the cream, intersecting thin streams of cream and steam at high velocity, and expansion of the cream-steam-water mixture followed by a return of pressure on the mixture may be used.

The Venturi device has a pair of outlet ports 20 and 28, respectively, communicating with the steam and fluid chambers 22 and 23 supplied by the inlets it and i9, and which ports 2t, 2! are restricted and controlled by the adjustable valves 24 .and 25, respectively. The valve 25 is regulated by engagementof the nut 26 with the threaded sleeve 21; the valve 24 is carried on a stem 23 having adjustable threaded connection with a bushing 29 and the stem is provided with a'handle 39 for regulating the adjustment. The ports 20, 2| are continuous, concentric and preferably circular, and the size of the openings is minutely controlled by regulating the valves 24, 25, as described.

The steam port 20 is defined by inwardly di-- rectcd closely spaced sides, one having greater inclination than the other and forming a tapering restricted continuous opening whereby the steam supplied at a. gauge pressure of eighty to one hundred pounds, i. e., 325 to 340 F. to chamber -22 is ejected substantially in the shape of a. cone or fine stream at high velocity into the constricted portion 3| of the venturi and the adjacent enlarged portion 32 thereof. The outlet port 2 I for the cream is defined by parallel, continuous inwardly directed sides closely spaced, 1. e., forming a restricted outlet, whereby the cream introduced to the chamber 23 under a pumping pressure and compressed by cooperation of the pump with the restricted outlet port 2|, is broken up and similarly discharged substantially as a cone or fine stream at high velocity with the assistance of the aspirating efiect created by the steam,

jet, and intersects the stream or cone of high velocity steam. The thin intersecting streams of steam and cream ejected at high velocity create in the gradually enlarging or tapering side 32 of the venturi a condition or zone of reduced pressure. This tapering portion 32 at its widest diameter merges into or is connected into communicating relation with the line A, as shown at 33. Referring to Figure 13, the cream in chamber 23 is subjected to a heating by contact with the heated wall of the steam chamber 22.

There takes place in the treatment just described (a) compression and heating of the 5 cream. (b) a tearing apart of-the cream particles by reason of the bombardment of steam and cream, (0) an expansion of the cream-steamwater mixture thus produced, resulting in further and more intimate subdivision in the zone de- 10 fined by the tapering portion 32, and then (at) compression of the mixture as it fills the conduit A as a liquid column. Subdivision of the cream is thus very complete and fine, and the odoriferous andofi-iiavor imparting substances are rc- 15 leased or rendered potentially releasable. Initial pasteurization and sterilization also take place and are completed in the line A-B. The heated mixture in the line A--B is agitated and compressed and an intimate mixture of steam with 2c the cream particles is maintained. This agitation and compression continues during travel of the mixture in the line A-B whereby the released volatiles, under conditions prevailing in the line, will be prevented from returning to their 25 former combined state, and ,the release and potential release of additional undesired substances will occur; also the cream is enhanced so far as rendering potentially releasable the more tenacious substances. This preliminary conditioning of the cream and its pasteurization is aided by the high temperature of the mixture, namely 200 to 250 F. and higher.

While in Figures 1, 2, 6 and 12 the steam injection means is disposed horiaontal it operates 35 with equal facility when disposed in a vertical plane.

A feature of this construction of particular importance resides in the minimum of control re-' quired. For example, the valves 2 25 can be set 40 and the steam and cream at predetermined temperatures and pressures passed to the injection device G, whereupon a constant temperature will be maintained, with uniform heating and subdivision of the cream.

A greater subdivision is, moreover, obtained in the vacuum chamber ii by reason of the fine subdivision resulting from this preconditioning. The restricted outlet in the head it may, in some instances, be adjusted as low as ten cne-thousandths so of an inch (.010") without retarding the speed ofoperation. At the same time, the most tenacious and stubborn odoriferous and off-flavor substances are removed. As to the latter element of speed, the high velocity treatment speeds up the flow and, moreover, prevents clogging or coating of the injection device or the line, since uniform heating takes place and little or no opportunity is presented for precipitation of curd which would tend to collect in the line were there any uneven on heating or overheating.

The subdivision of the cream by using the injection device C in cooperation with line A --B- I5 and associated devices is very effective and emclent so far as pasteurizing, and release or potential release of volatiles, is concerned, because of the initial bombardment of a thin continuous high velocity stream of cream with a similar stream of steam'and followed by (1) expension and (2) compression, since there actutroduced through fluid-tight fittings into the upper and lower ends of the conduit A as shown at 36, and to heat'the fluid in the line to a pasteurizing or sterilizing temperature. 'For example, an inert gas such as steam at eighty-to one hundred pounds gauge pressure and at a temper- 'stantially 30.

ature of approximately 325 to 340 F. is injected into the fluid in the conduit A, through the nozzles 35.

The nozzles 35 are disposed inspaced relation in the conduit A and extend toward one another as shown. Each nozzle is provided with a plurality of narrow or small diameter spirally arranged spaced ports (about inclined at sub- The ports 31 open upwardly, i. e., inject the steam in the direction of travel of the cream flow; the ports 38 open downwardly, while the opposed longitudinal ports 39 of the respective nozzles inject the steam parallel to and reversely of the cream flow. In this manner, a turbulence and whirling of the fluid is obtained, assuring intimate mixing and uniform heating of the fluid, and compression of the cream-steam-water mixture because of the pressure created (1) by the heating effects, (2) by the steam in cooperation with the pressure created by (3) the restricted outlet in the distributor head at one end of the line and the pumping pressure at the other end. A very complete subdivision of the particles in the case of milk and cream with resultant enhanced release and potential release of volatiles and odoriferous substances therefore is obtained.

The ports 31 preferably number about twenty while the ports 38 number about twelve and the ports 39 about four. This ratio may be departed from as desired but it is preferable that the ports 31 injecting steam in the direction of cream flow predominate. The ports may be formed throughout the length of the nozzles or only partially as shown.

In operating the apparatus at a gauge pressure of approximately 10-15 pounds in the lineA-B, the fluid, when it reaches the vicinity of the upper nozzle, has a temperature of substantially 190 to 205 F. and this is raised to about 210 to 230 F. by the steam treatment at this point. The temperature of the cream-steam-water mixture will be controlled through the medium or this upper nozzle. For example, it has been found with a vacuum of twenty-four inches to twentysix inches in the chamber 9, that a gauge pressure of about ten to fifteen pounds and temper ature 01 210 to 230? F. for the cream-steamwater mixture in line A'B will produce very satisiactory results. Therefore, we associate with the upper nozzle a thermostatic control indicated as a whole at 40 as shown in Figure 5 to regulate the steam injected and by consequence adjust the temperature of the cream-steam-water mixture. In the use 01' the ejector D, very satisfactory pasteurization and subdivision of thecream particles is accomplished in line A-B by injecting live steam under pressure through the spaced ports 31, 31, 39 of the nozzles 35 in the form of needle-likejets and into the cream. This produces a multiplicity of impacts or impingements by the steam on the column of cream travelling in the line A--B whereby mixing of the steam and cream takes place in a manner to agitate and thoroughly comb the steam with cream. Due .to the spacing and angular disposition of the ports, a turbulence and whirling in the direction of travel is imparted to the cream-steamwater mixture. Substantially similar eflects and results are obtained as with the injector device C, but the latter gives more positive control and is more effective.

In connection with the use of a pump, this, in association with the distributor head I6, and either injection device C or D, increases the of- 5 fectiveness of the process and the capacity of the apparatus materially' Where the injection device D is employed, the temperature of the mixture in line A--BI5 is regulated by the thermostat 40, and the pressure head in line A-'BI5 is adjustable by regulating either the pump or distributor head IE or both. These controlfeatures are all available and employed where the injection device C is used but ordinarily by reason of the relatively finer adjustments afforded through the use of the venturi, no thermostatic control 40 is needed.

Hence, it is possible to exercise a precise control, and the condition of the cream-steam-water mixture, i. e., temperature and pressure, in 20 the line A-B is susceptible of nice regulation at all times, using either injection device to acccmplish optimum results. As will be appreciated, this is very important in a continuous system such as comprehended by the present invention, assuring both uniform and complete pasteurization, and subdivision of the creamsteam-water mixture. Stated briefly, the treatment of the fluid in line A-B is maintained substantially constant and the cream is introduced 30 through the distributor head in optimum condition for the instantaneous, and explosive expansion, to which it is subjected in the vacuum chamber and a desired pressure difierential'of about two atmospheres is constantly held between the vacuum chamber 9 and the line A-B.

The line [1-3, it will be noted, is relatively long and this allows of very complete pasteurization as well as an extended time period for utilizing the compression effects to (1) subdivide the cream and (2) accomplish release and potential release of objectionable substances.

The cream-steam-water mixture in the line A-B is distributed in the vacuum chamber 9 by means of the distributor head lfi which has a 45 narrow, preferably'elongated or continuous peripheral, opening 4|, as will be later set forth in detail and as shown in Figures 21, 22 and 23. At the opening 4|, the pressure of the creamsteam-water mixture in the line AB is suddenly released due to the reduced pressure in vac- I uum chamber 9 and it is expanded with spontaneous and violent force downward into the chamber. We have found that a pressure difierential of substantially two atmospheres between 55 the line AB and the vacuum chamber-will produce very excellent results. The vapors and gases released by the expansion of the creamsteam-water mixture in the vacuum chamber 9 through head l6 are carried off through a port 42 and pipe 43 to the condenser 44 and vacuum pump 48 as shown in Figure 5. The liquid portions of the cream or milk will coalesce and collect at the bottom of the vacuum chamber 9 and will pass by outlet-pipe to a suitable pump 50, so that the coalesced liquid can be continuously 4 removed through a pipe 10.

Referring to Figures 1 and 2, 12, 30, 31 and 32, in some cases where excessive concentration of objectionable substances are present or they are tenacious, the coalesced liquid having a temperature of substantially F. to F, is subjected to a steam scrubbing treatment.

In the process and apparatus shown in Figures 1 and 2, the cream-steam-water mixture is dis- 7 aoaaeeo charged with violent expansion and assumes a fog-like state substantially within the confines of a receiving member 5! of generally cup-shaped form (Figure 1) or an inclined baflle 52 (Figure 2) supported in the vacuum chamber. The receiving member 5! has an inclined bottom terminating in a pipe 53 and the bottom of the chamber 9 is divided by a plurality of partitions 54 shown in detail in Figures 3 and 4, defining ccmpartments 55, as shown in each of Figures 1 and 2. The baffle member 52 and the pipe 53 are adapted to discharge the coalesced cream into one of the end compartments continuously as shown. As many compartments may be employed as desired, and they are made communicative by outlets 53.

In each compartment 55 is disposed a perforated steam pipe 5? which supplies live steam at a suitable temperature and pressure for scrubbing the portions of coalesced cream collected in said compartments. A sufficient number of openings are provided in the pipes 5? to impart an agitation and turbulence to the cream portions undergoing steam scrubbing in the vacuum chamber.

The outlets 56 are disposed at a level such that flow of cream from one compartment to the other will take place continuously and the height of each bafile or partition 55 above each outlet is such that foaming over is avoided. In this connection, the ends of the partitions M are bent over as shown at 58 so as to divert any foam back into the mass portion under treatment.

With the apparatus shown in Figures 1 and 2, successive portions of coalesced cream are given a consecutive steam scrubbing in each compartment. The flow is continuous and the treatment simultaneous with, i. e.. in the presence of, the fog produced upon the introduction of and expansion of the cream-steam-Water mixture in the vacuum chamber 9. The finally treated cream is withdrawn through the other end compartment by the medium of the pipe 49 and pump til and thereafter suitably cooled. In this connection, control of the flow through the compartments is provided for by regulating the quantity of cream-steam-water mixture introduced to-the vacuum chamber through the distributor head it. Additional outlet pipes 39' preferably for drainage purposes are provided having suitable valves 50, the pipes 49 and =39 being connected to a line 59 leading to pump 5|].

The objectionable volatiles separated by the expansion treatment and volatilized and swept out in the steam scrubbing operation are drawn oil through the port 42 and pipe 43.

The process and apparatus of Figures 1. and 2 involves using a single vacuum chamber for accomplishing simultaneous and continuous (1) in troduction of the cream-steam-water mixture into the vacuum chamber and expansion thereof into a fog or mist. (2) steam scrubbing of the collected coalesced cream in the presence-of the mist, (3) removal of the objectionable vapor phase constituents resulting from each of these operations, and (4) removal of the finally treated cream in a steady stream.

The vacuum chamber 9 is also useful for scrubbing batches of coalesced cream. Thus, the c eam is collected in one or moreof the compartments 55 to a desired level, whereupon the discharge of the cream-steam-water mixture through the distributor head I6 'is stopped and the steam scrubbing means 5! operated. 1

The simultaneous scrubbing or operation of the batch treatment immediately subsequent'to the expansion treatment before the batch has cooled is advantageous in that the coalesced cream is at a temperature sumciently elevated to render the steam scrubbing immediately effective, there- 5 wall t5 constituting a jacket which is heated electrically or within which is circulated a heating medium either of gas or liquid but preferably hot water. The temperature of the heating jacket should be about twenty degrees above the term 20 perature in the vacuum chamber and under conditions of twenty-four to twenty-six inches of pressure in the chamber ii, the inner wall of chamher 9 should have an approximate temperature of 165 to 150 F. The inlet and outlet for the '25 circulating medium are indicated at 66 and ti, respectively.

The heating jacket 65 assures that the inner wall surface of the chamber 9 will be at a constant temperature and serves to reduce to a min so imum the possibility of condensation of water vapors and gases on the wall, as well as-produce a prolonged separation of vapors and odoriferous and off-flavor gases from the liquid phase particles. This heating jacket 65 serves to maintain the wallof the chamber 9 at all times heated to the temperature above the boiling point of the cream, according to the conditions of vacuum in the chamber 9. As heretofore stated, a temperature at least twenty degrees above that of the chamber 9 should be present in the jacket $5 for maintaining the wall at elevated temperatures.

Thus. a heated vacuum chamber is employed, the heating meansbeing constituted by the jacket 55 and steam scrubbing and distilling means 5?. 45 In some cases, the jacket 65 may be omitted but its use is preferred.

perature corresponding to its boiling point under 55 the conditions of vacuum being maintained. Under the conditions recited, namely twenty-four to twenty-six inches of vacuum, this temperature normally is reduced to about 145 to F.

High pressure live steam is preferably wed in 60 the scrubbing means, e. g., eighty to one hundred pounds gauge pressure and each portion in the I continuous flow'or in batch scrubbed for a. varying period, usually short, e. g., five to ten minutes depending on the cream.

A feature of the process resides in the fact that the steam scrubbing treatment is performed under conditions whereby the coalesced cream retains substantially its original form without being appreciably condensed or diluted. The effect 70 of the steam sweepingthrough the cream is (1) to vaporize to some extent and (2) particularly to mechanically remove any remaining small concentrations of odoriferous and off-flavor imparting substances. 75

Figure 31, instead of carrying out the scrubbing operation in accordance with Figures 1 and 2, the coalesced cream either continuously or as a batch is pumped from chamber 9, at a temperature of about 130 to 145 F. by means of pump 59 through a line 10 to a vacuum still or steam scrubber I I. This scrubber is of conventional design and'comprises means such as a steam pipe or injector 51 for injecting steam into the cream and steam scrubbing the same. The volatiles are withdrawn through the outlet 42', 43 and the treated cream is carried off by the line l2 from the bottom of the still. The vacuiun distillation or steam scrubbing will be carried out at a vacuum of substantially twenty-four to twenty-six inches in the still and the cream need only be treated for a short time as above explained. The cream is collected through the line 12 in either Figures 1 and 2 or Figure 31 and passed through a cooler 13 where its temperature is reduced to about '70 to 80 F. From the cooler, the c eam is carried to a suitable storage tank 14.

In some cases and referring to Figure 12, the vacuum chamber 9 is equipped to operate also as a vacuum still substantially similar to the vac- 4 scrubbing as described herein is speedy and ecopipes 15 provided with shut-off valves 15, so that expansion and collection in one or more chambers 9 will take place while scrubbing and distillation of a batch of the cream previously collected in the other of said chambers is being carried out. A draw-off line 59, .connected in multiple with the bottoms of said chambers by pipes 49 having suitable shut-off valves 59', is provided,'and the finally treated cream is selectively drawn off by pump 59 and carried by line 12 and cooledor otherwise treated as herein described.

Such scrubbing treatments of the cream are advantageous in that they may be (1) continuous with the previous expansion treatment, or (2) operate as a batch process, and in each case this is readily accomplished with saving of steam since the cream as recovered in or from the vacuum chamber 9 is at a sufilcient temperature not to require a further heating before treatment with the scrubbing steam.

Any of the several processes involvingsteam nomical and, as stated, will be used in some cases to remove excessive concentrations of objectionable substances .or where such substances are unusually tenacious. The results obtained are exemplified in the case of cream used in butter making, where the butter has been found to have a score advantage of from two to three points higher than that obtained by conventional methods.

The steam scrubbing will, in some instances, as will be appreciated, not be necessary to produce a butter of a satisfactory score or quality, the previous operations of the process being sumcient.

Referring to Figure 32, instead of subjecting the cream from the chamber 9 to a subsequent distillation treatment, this treatment can be made. preliminary to the introduction of the cream to the surge tank In. However, we do not prefer the preliminary treatment since, where the 5 cream is subsequently scrubbed, no further heating is required, and the distillation can be accomplished as a continuous step in the processing of the cream. Where the distillation or purifying treatment precedes the pasteurizing and deodor- 1 izing operation, the cream from the supply Bil-is passed through a flash p'asteurizer or other conventional heater 8| and the temperature thereof raised to about 130 to 145 F. Thereafter, the cream is passed through line 82 to a still H and 15 subjected to asteam scrubbing as heretofore described. The cream is carried by the line 83 to a flash pasteurizer 84 and treated at a temperature of 1'70 to 180 F.,'whereupon the cream is passed to the surge tank l9. 20

In some cases, this preliminary steam scrubbing is combined in a process using a simultaneous scrubbing as in Figures 1 and 2 and/or a subsequent steam scrubbing as in Figures 12 and 31.

A preferred form of distributor head I 9 is illus- 5 trated in Figure 21. This head comprises the body portion 90 having an extension 9| within which is swaged or soldered, to provide a sealed joint, the end of pipe [5. A valve 92 is adjustably connected to the body portion 90 through the medium of bolts 93 and wing nuts 94. Sleeves 95 surround the bolts 93 and act as spacers for the valve 92. Suitable shims 96 may be interposed between the sleeves, and either the body portion or preferably the inside surface of the valve, as shown, to allow of a very fine adjustment of the outlet 4|. That is to say, we employ a distributor head having means to permit of an extremely fine and critical range of adjustment for the outlet opening In this connection, the outlet opening is substantially continuous or elongated and, as shown, is relatively narrow. The bafile 91 is connected to the head and supported thereby as shown, and diverts the finely divided particles downwardly in the vacuum chamber to reduce possibility of entrainment.

Referring to Figures 22 and 23, there are disclosed modified types of distributor heads which are precisely of the construction shown and described in the application of Herman C. Homeman, Serial No. 681,658. Either of these constructions may be employed as desired, but it is preferred to use the construction shown in Figure 21- and above mentioned.

Referring to Figure 22, the distributor head comprises a body 90 and valve 92 adjustably connected by bolts 93 to vary the width of the spray outlet 4|. The bolts are provided with wing nuts 94 engaging springs 98 disposed between each wing nut and the adjacent surfaces .of the body 99. Interiorly of the member 99 are projections 99 through which the bolts extend and which projections are of equal length and of a size whereby suitable shims 96 may be interposed between the bottom of the projections and the top surface of the valve 92, thereby affording an extremely fine and critical range of adjustment for the outlet opening 4 l The valve 92 has an opening receiving the end of line IS, the end of the line being flanged and soldered to the valve as shown.

Referring'to Figure 23, the distributor head l9 comprises the two members 99, 92 which are centrally connected by a single bolt 93 and arranged about the bolt are a plurality of spacer members 95 having reduced ends loosely disposed in the members 99 and 92, respectively. When it is desired to adjust the outlet opening between the body portion 99 and the valve 92 and, if required, suitable shims 96 are fitted about the reduced ends of the spacer members 95 to assure a very fine adjustment of the outlet opening 4|, as described in connection with Figure 21. The line i5 is connected to the'valve 92 in the same manner as in Figure 22, extending through the opening '9 I in the valve.,

Referring to Figuresl8 and 19, the .outlet $2 of the surge tank is controlled by a float actuated valve I99. The mechanism for operating this valve includes the float l'fll having connected thereto an operating rod 302 pivoted on the bracket I03 carried by the wall of the surge tank, the free end of the rod I02 engaging the link not which, in turn, is freely connected to a lug I95 carried by the valve liii). The valve m is rotatablymounted on a bolt or stud Hi6 mounted in an extension ID? of the outlet i2 and a spring )8 is interposed between the head Hi9 of the stud and the inside wall of the extension N11 for maintaining the valve flush with the inside wall at all times. The rotary valve has an opening III] which is in register with the opening in the outlet I2 when the liquid and the float are at a predetermined level. ed from, the float will act to partially or entirely close the valve until the required level is again reached in the surge tank.

The float valve structure illustrated in Figure 20 is precisely like that shown and described in the aforesaid Horneman applications and comprises a float iiil carried by a lever E92 pivoted to the wall of the surge tank iii at Hi. A lever i i2 is pivotally connected to the arm it? and to a valve I I3, forming a slide operated valve mech= anism, the operation of which will be readily understood, for controlling the opening and closing of the outlet i2.

In Figures 18 and 19, the float is shown at the predetermined level with the opening H9 registering with the opening in the outlet i2, while in Figure 20 the float is shown in its lowered position with the valve H3 closing the opening in the outlet l2. The purpose of employing float valves of the type illustrated in Figures 18, 19 and 20 is to overcome any possibility of releasing, the vacuum in the chamber 9 if the liquid reaches a predetermined depressed level as when the cream supply temporarily stops. In some cases, the float structure may be omitted and a simple gate valve,

manually or automatically operated, positioned at the outlet l2 leading to the pump.

The distributor head- I6 is relatively small as compared to the size of the vacuum chamber 9, as shown. It is preferably substantially centrally located, that is, s ufliciently below the outletport 42 in the chamber 9 to prevent entrainment and far enough from the bottom of the chamber to give the falling particles projected fromthe head a sufficient time for adequate separation out of the vapor and liquid phase constituents and cooling of the latter. These conditions are preserved in Figures 1 and 2 as well as in the other apparat-us shown.

The line AB and/or line i 5 is of a length and d ameter to enable the lactic fluid to be continuously pumped to the head is and, as stated, during this travel the lactic fluid is simultaneously pa teurized and intimately mixed with the steam to be compressed, broken up and subdivided under the conditions created in the line AB.

When this level is dcpart- As heretofore stated, the cream introduced into the line AB is continuously under the influence of (a) the heating effects, (b) the pumping pressure of the pump P, (c) the steam pressure impressed upon the fluid, and (d) the back pres- 5 sure created by reason of the restricted outlet 4! in the distributor head l6 cooperating with said pressure components. The cream or fluid is consequently thoroughly pasteurized and subdivided to obtain a preliminary, but nevertheless very complete subdivision of the particles and the.

oream-steam-water mixture. is brought, by means of the control provided, to optimum condition and temperature and pressure for introduction into the vacuum chamber through the distributor head. That is to say, the subsequent explosive expansion to which the steam-cream-water mixture is subjected in the vacuum chamber will result in the maximum release of volatiles and odoriferous substances. These latter will be continuously removed through the port 42 and the cream will continuously coalesce in a highly purifled condition and be collected in or from the bottom of the vacuum chamber 9.

In Figures 7 and 8, we have illustrated further examples of apparatus which are precisely those shown and described in the aforesaid Horneman applications.

The constructions shown in Figures 7 and 8 comprise a vacuum chamber 9 and surge tank It to which fluid is supplied through a'pipe il as described in connection with Figures 1 and 2. The surge tank 59 has a laterally'extending outlet i2 as shown in Figures 18, 19 and 20, and the liquid is transferred through the pipes Ht, Wt to the vacuum chamber 9, flow in the direction of the vacuum chamber being created by reason of the pressure differential being maintained between the liquid in the line 929, ME and the vacuum chamber 9. A steam line E22 has its 40 open or nozzle end introduced in the line 529 above the outlet i2 and steam is introduced under pressure and in sufficient quantity to heat the liquid in the line H29, Hi to a pasteurizing or sterilizing temperature; which temperature and pressure are automatically maintained by a thermostat control i23 activated from the bulb at I24. The cream-water-steam mixture from line [20, i2! is distributed in vacuum chamber 9 by a distributing head it similar to those already described and shown in detail in Figures 21, 22 and 23, through the narrow, preferably elongated or continuous peripheral opening 4|. In Figure 8, the vapors and gases released by the introduction of the liquid steam-water mixture 65 into the vacuum chamber 9 through the head I6 are carried off through the port 42 and pipe 43 to the condenser 44 and pump 48 as shown also in Figures 1, 2, 5 and 9. In the apparatus of Figure 7, a plurality of spaced outlet ports 42 as shown in detail in Figure 10 are employed, and an ejector-condenser system indicated as a whole at I25 is utilized instead of a wet pump 48.

Either an ejector-condenser system 125 or a wet pump and condenser 48, 44 are employed with each of the vacuum chambers or vacuumchamber-stills shown and described herein, and this is likewise true of the suction outlet meansshown in Figure 10.

Referring to Figures '7 and 8, the present differential between the line I 29, I2! and the vacuum chamber 9 and the relatively narrow outlet opening 4| in the head causes a spontaneous and violent separation of the mixture in the vacuum chamber. That is, the liquid and vapor phases are discharged through the narrow elongated outlet 4| and are broken up or particulated into substantially a fog from which the cream or milk on the one hand and the water vapor and gases on the other separate out in the chamber 0 as with the process shown in Figures 6 and 2.

The vacuum chamber 0 is provided with a heating jacket 05 similar to that described in connection with Figure 2, which serves to reduce to a minimum the possibility of condensation of water vapors and gases on the wall of the vacuum chamber as well as produces a prolonged separation of vapors and odoriferous gases from the liquid phase particles.

The liquid portions of the cream or milk will coalesce and collect at the bottom of vacuum chamber 9 and will pass by outlet 40 through a cooler system I3 and can be continuously removed and recovered from the vacuum chamber by means of line 59 and a suitable pump 00 and discharged through pipe [0.

In some cases, the apparatus of Figures '7 and 8 will be associated with a preliminary distillation as described and shown diagrammatically in Figure 32 for continuously pre-treating the lactic fluid before its introduction to the surge tank I0, all as heretofore described. In other cases, the cooler will be disconnected and the cream from 'the vacuum tank 9 will be continuously pumped through the line to the still II all as shown and heretofore described in connection with Figure 31. -Of course, both a preliminary treatment as shown in Figure 32 and a subsequent distillation treatment as shown in Figure 31 will be used if desired.

The line I20, I2I in some cases will be made similar to the line A-B described in connection with Figures 1, 2, 5, 6 and 12, in which event, the pipe I20 will be elongated to receive the steam injectors C or D and associated with a pump P and a thermostat 40 if required, as heretofore described.

In Figure 9, we have illustrated a further construction which is precisely like that shown and described in the aforesaid Horneman applications wherein one or more peripherally disposed spray nozzles I26 are provided. These nozzles I 20 are preferably spaced apart and the jet opendered dairy products by a spray process. The

nozzles, as shown in. detail in Figure 24, each have a spirally grooved and loosely confined member in advance of the outlet port and will produce the so.-called solid cone spray.

The construction shown in Figures 9 and 24,

can be embodied in each of the other apparatus illustrated in Figures 1 to 12 and Figures 25 to 29, as desired, and such apparatus will be equally operable with either a construction embodying the line I20, I2I, as shown in Figure 9, or a pump P and line A'B with injector device C or D. The apparatus shown in Figure 9 is capable of being operated as a continuous system in association with the scrubbing apparatus described in con- 'nection with Figures 1, 2, 12, 30, 31 and 32.

-In Figures 25 to 28, inclusive, we have illus trated various forms of vacuum chambers, particularly modifications of a heated vacuum chamber. In Figure 25, the vacuum chamber is heated by a coil I21, disposed below the distributor head;

in Figure 22 the coil I21 surrounds the distributor head; and in Figure 27, the heating coil is disposed above the head. Any of the three dispositions of the coils may be used or combined in any suitable manner with the vacuum chambers or vacuum-chamber-stills herein described.

Instead of using a circulating medium such as hot water or a gas, the coil may be provided with an electrical resistance element as shown in Figure 28 or the jacket may be provided with anelectrical heating unit as shown in Figure 29.

In Figure 11, we have illustrated a-means of supply as a heated circulating medium such as hot water to the jacket 65 of the vacuum chamber 0 or to the coil I21. The warm water from the condenser shown in this system or that shown in Figure 5 is pumped through the line I28 in any suitable manner and a steam ejector I29 is employed to raise the temperature of the water, as desired. The, ejector I29 is controlled by a suitable thermostat I30 to regulate this heating of the water and assure that it will be delivered to the jacket or coil at a constant required temperature.

With each of the processes and apparatus heretofore' described, the fluid such as cream is pasteurized and subdivided in the line A-B or the line I20, I2I preliminary to its introduction into the vacuum chamber 0. The diameter of the line AB or the line I20, I2 I, the peripheral dimension of the members defining the outlet in the head I6, the size of the outlet, the diameter of the steam inlet, the temperature and'pressure of the steam, and the pumping pressure are selected or controlled to produce the required result. In other words, these parts should be so related that the proper pressure differential will be established and that sufllcient time will be permitted before the mixture enters the chamber (1) for intimate mixing of the steam and lactic fluid, and fine subdivision of the latter, and

(2) for reaching a temperature sufficient for pasteurization or sterilization.

The invention is applicable to milk, cream, ice cream mix and milk products in general and for convenience, we shall describe the treatment of sourcream (any cream in which the titratable acidity calculated as lactic acid exceeds 0.20%) to improve the same and render it satisfactory for the manufacture of butter.

Conventional practice comprises reduction of the acidity of the sour cream to a point at which satisfactory churning may be accomplished. Normally this point lies within a range ing and sampling and possesses various percentages of acidity.

' Process A In carrying out the preferred process, the apparatus illustrated in Figures 1,2, 13 and 14 is employed.

7 Initially, and referring to Figure 30, the cream as received is warmed to a point where it can be conveniently handled with the usual dairy equipment. Normally, this temperature'will not ex- 

